Archive for August, 2014

Since I last posted, AV-6 flew a successful mission over Cristobal. Meanwhile, AV-1 is still stuck in California until crews can figure out the electrical issues that are affecting the aircraft. Those of us on the AV-1 instrument teams, which includes the team I’m on, are starting to get pretty jealous of AV-6’s ability to actually fly. One of the most frustrating parts of being on an instrument team is waiting around until both your aircraft is available to fly and there is a good target for your aircraft to fly over. When we do get to fly, every instrument team has to staff the Global Hawk Operations Center, or GHOC. Thanks to multiple shifts of researchers and pilots, we can fly the UAVs for long lengths of time—all from the comfort of our desks! In the GHOC, researchers don headsets and monitor our instruments to make sure they are working properly; which is less flashy than it sounds. However, I still cannot wait to be a part of a flight. I’m staying patient and thinking positively about getting AV-1 here at Wallops.

On Thursday, August 28th, I was able to watch AV-6 take off from Wallops Flight Facility. The black plane that you can see in the linked video is flown as an added safety precaution as it follows the UAVs during take off to make sure no other aircraft crosses its path. The photo below shows what Cristobal looked like shortly after take off around 7 pm from the Geostationary Operational Environmental Satellite (GOES):

Slightly after AV-6 (green aircraft icon) took off from Wallops Flight Facility on August 28, 2014, Hurricane Cristobal was located just off the East coast of North America. This image is a combination of GOES visible imagery and a Google map for reference.

One of the challenges for mission scientists during this flight was that Cristobal was moving rapidly. Throughout the night, forecasters and scientists were altering the flight plans to account for the fast motion of the storm as well as commercial air traffic in the region, in order to get the best possible coverage of Cristobal. Overall, the flight was a success and the mission’s objectives were achieved.

While I was tracking AV-6 on the way home from Cristobal, I had fun looking at the imagery that was taken from a camera on the bottom of the aircraft. Below is a photo captured on the way home from Cristobal on August 29th:

Imagery from AV-6 on the way home from sampling Cristobal; Sunlight reflects off the Atlantic Ocean and clouds cast shadows onto the sea surface

After the excitement of Hurricane Cristobal, forecasters and scientists are looking for the next storm to target. The National Hurricane Center has given a tropical wave over the northwestern Caribbean a 60% chance of tropical cyclone formation over the next 5 days. This system will likely be AV-6’s next target in the Bay of Campeche on Tuesday, September 2nd. If you would like to follow along with the flight you can track AV-6 on this page.

Welcome to the HS3 blog! My name is Mary Morris and I am a graduate student studying atmospheric science at the University of Michigan. Over the next few weeks I will be posting about my experiences while I participate in the HS3 mission at NASA Wallops Flight Facility.

HS3 is a mission designed to investigate the processes that control hurricane formation and intensification. In order to collect observations of hurricanes we have two unmanned aerial vehicles (UAVs) outfitted with meteorological instruments that we can fly for long distances to reach hurricanes and storms forming in the Atlantic Ocean basin. On one of those UAVs, AV-1, is an instrument called the Hurricane Imaging Radiometer, or HIRad. My graduate research is currently focused on extracting surface wind speed and rain observations from HIRad data, so participating in the collection of HIRad data is an exciting opportunity. While the HIRad team has been here at Wallops since August 25th, we are still awaiting AV-1’s arrival. Until then, HS3 scientists will be relying solely on the other UAV, AV-6, to investigate hurricanes.

AV-6 arrives at the Wallops Flight Facility on August 27, 2014

Wallops Flight Facility (WFF) welcomed AV-6 back from Armstrong Flight Research Center (AFRC) on August 27th. On the way to WFF, AV-6 was able to get a good set of observations of Hurricane Cristobal. In order to collect data on the storm’s environment, AV-6 uses three types of instruments. First, dropsondes are—you guessed it—dropped from AV-6 to gather information about air temperature, dewpoint, atmospheric pressure, and winds. Dropsondes are similar to weather balloons. The Scanning High-resolution Interferometer Sounder, or S-HIS, is used to gather information about air temperature and water vapor. And finally, the Cloud Physics Lidar, or CPL, is used to gather information about clouds and aerosols in the atmosphere. All of these observations are helpful for analyzing the environment of a hurricane.

Since the UAVs can fly long distances, we are going to get a good second look at Cristobal later tonight and tomorrow. HS3 scientists are particularly interested in observing Cristobal as it interacts with a frontal zone. As Cristobal interacts with the frontal zone, it will lose the characteristics that make it a tropical cyclone and gain characteristics that will make Cristobal an extratropical cyclone. In short, the differences between these two types of cyclones have to do with where the cyclones get their energy. With the NOAA Hurricane Hunters collecting data on Cristobal from the beginning, and with HS3 following up on Cristobal tonight, atmospheric scientists will have lots of observations that document Cristobal’s life cycle. These observations will then help scientists as they continue to research the processes that underlie hurricane formation and intensification.

Update: The R/V Endeavor returned from sea on Aug. 6, concluding the fieldwork component of the 2014 SABOR experiment.

As mentioned in the previous blog (“A Vast Ocean Teeming with Life”) ending this cruise is not an easy thing to do. Especially if you experienced the majesty of the crystalline blue water in the open ocean as well as the magnificence of the wildlife surrounding it for the very first time. I am currently coursing my third year as a PhD student in the Electrical Engineering Department of The City College of New York (CCNY). I work as a research assistant for a small department in the Optical Remote Sensing Lab called Coastal and Oceanic waters group. We may look like a group of cool guys going out for fishing (as it seems on the left side of the picture), however, we are a team who works hand to hand together (depicted on the right side of the picture … why does the right side always seem right?)

“Cool guys” aka Coastal and Oceanic waters group, members of the ORS Lab at The City College of New York (CCNY). Courtesy of Lynne Butler

My research consists of using polarization properties developed as the light field propagates through the water body and use this information to characterize and retrieve water constituents and inherent optical properties (also called IOP’s) from polarimetric measurements. The basic idea is that as light propagates through the water it experiences significant attenuation due to absorption by water and suspended/dissolved matter as well as scattering by water and suspended particulates. These effects, both absorption and scattering, result in signal degradation of the radiance captured by sensors in our instruments. The additional information obtained when using polarization properties of underwater light propagation can provide a better understanding of this propagation and methods for improving image quality and increase underwater visibility … wait! (at this point you may be asking yourself).

So how can this have a real contribution to the goals and objectives pursuit by the SABOR (Ship-Aircraft Bio-Optical Research Campaign) cruise? Well, the answer could be very simple. The ocean is too big and in-situ measurements are too expensive to cover the entire water mass on Earth. Having this in mind, it is very clear that we need to adopt another cost-effective approach and that is the reason why we use satellite observations to account for many changes that take place in the ocean and coastal waters. Satellites provide very useful information when properly calibrated. As you may already know, sensors deteriorate over time and satellites go out of commission. However, polarization features are preserved even when the sensors may have experienced normal degradation and knowledge of this features can contribute in the development of future technologies to be used in satellites when more accurate and reliable information is to be acquired. Some living and manmade objects in water have partially polarized surfaces, whose properties can be advantageous in the context of target camouflage or, conversely, for easier detection. Such is the case for underwater polarimetric images taken to detect harmful algal blooms (red tides) or to assess the health of marine life and coral reefs which are of significant scientific and technical interest.

The main challenge faced by these images is that of improving (increasing) the visibility for ecosystems near and beyond the mesophotic depth zone. Data collected in the form of images, videos and radiance was acquired using a green-band full-Stokes polarimetric video camera and measurements of each Stokes vector components were collected as a function of the Sun’s azimuth angles. These measurements are then compared with satellite observations and model using a radiative transfer code for the atmosphere-ocean system combined with the simple imaging algorithm. The main purpose of this task is to validate satellite observations and develop algorithms that improve and correct these observations when needed.

But seriously… Are you playing video games? Courtesy of Lynne Butler and Ivona Cetinic

It always looks like I am playing video games but in order to have very accurate information it is advisable to position the instrument at a certain orientation with respect to the Sun’s azimuth angle. The instrument depicted here is called Polarimeter and as Robert Foster suggested in his blog it has a very boring name, so we are still in search of a cool code name after someone suggested (unsuccessfully, and I am glad for this) to call this instrument Carlos. A real issue came across when they were thinking to put Carlos in the water … an idea that I didn’t share. The polarimeter, let’s forget about Carlos for a moment, is a set of Hyperspectral Radiance sensors with polarizers oriented in the vertical, horizontal and 45° from a reference axis. This sensors can capture light coming from any point in the water body thanks to a combination of a step motor which can be programed to stop in any sequence of angles in the range of 0 – 360° (from vertically up to vertically down) and a pair of thrusters (or propellers) which can rotate in the azimuthal direction (both clockwise and counter-clockwise). This scenario allows for vitually a 3-D range of hyperspectral measurements. Pretty cool, huh? The set of bouys at each corner allows us to have a very stable system and prevent the instrument from going very deep down in the case that cables and safety line get cut.

When things go like they do in the left image, we always have to do the right thing. Courtesy of crew members and Ivona Cetinic

Very far from what most of us have probably experienced in a cruise or fishing trip, the ocean is not always calm. In our twenty plus days in the ship, we came across a system which was playing very rough against the R/V Endeavor. Fortunately for us, this cruise was under the supervision of very talented and experienced people. I am not talking only about the captain, but also his outstanding crew members, chief scientist and marine technician. Although we have some minor difficulties (… you should know by now that sea water and electronics will never be good friends) we fixed them as soon as the storm was gone. It is not that Robert and I are playing as firefighters rescuing a dispaired kitten from a tall tree.

I want to end my vision of this field campaign with a summary of the awesome marine wildlife that somehow approach to us to say hello, some species more shy than others, to this group of scientists which were part of NASA-SABOR. As depicted in the picture (left-to-right and top-to-bottom), one of the first appearences was that of a seagull. It doesn’t look that shy since it preferred posing for us on top of the Polarimetric Lidar (owned and operated by scientist from NRL). Very intelligent creature this particular one, the others were just swimming in the waters and preparing to be a snack for a hungry shark as depicted in the image in the top center. Another interesting character which showed up near the surface was previously mentioned by Matthew Brown from Oregon State University in the previous blog post and it was a species of blueish salp with very long tentacles. The next creature is a very friendly dolphin which pretended racing us so we could take very amazing pictures. Dolphins always so adorable, appearing in pods and jumping out of the water around the research vessel or just posing underwater in front of the polarimeter! The last living character was a very shy sperm whale. Always keeping the distance but letting us know it was present leaping out of the water at most 300 feet from the ship!

These past three weeks in the R/V Endeavor had been very amazing although intense. Waking up and knowing that you are far from home, your friends and family may sound questionable but understanding that you are in front of one the most wonderful and powerful sources of life is a priceless experience not all of us can witness. That is why I am writting this blog and I hope you have enjoyed reading all our blogs and could have a taste of what is like being in the sea for three weeks!

Three weeks at sea is a long time for someone who has never been out of sight of shore. My greatest impression during my time out here is the one I first had when we first set out: the ocean is really, really big! I realize that probably sounds too obvious to be worth mentioning, but the sheer vastness of the ocean is hard to overstate. Standing on the deck, turning 360 degrees and seeing nothing but smooth, blue water as far as the horizon, it’s hard not to be struck by how empty it all appears.

Of course, that’s not true at all. The ocean, far from being empty, is teeming with life. Most of it is too small for us to see with the naked eye, but it’s there all the same and it affects each and every one of us even if we’ve never been to the sea in our lives. Phytoplankton, the microscopic algae that live in the sunlit regions of the ocean, not only provide much of the oxygen we breath, they also play an important role in managing the earth’s climate through their roles in uptaking CO2 from the atmosphere and cycling nutrients like nitrogen and sulfur through the ecosystem.

A big part of what our group does is trying to understand how different aspects of the ocean environment (light, nutrients, grazing pressure) affect the ability of the phytoplankton to photosynthesize and grow. One way we do this is through a piece of equipment called a fluorometer, which can give us an indication of how efficiently algae are absorbing photons from the sun and turning their energy into carbon. It works by hitting them with a large amount of light, then measuring what percentage gets released back after getting absorbed. A simple enough technique in principle but one that can tell us all sorts of things, from the size of the molecular antennas the algae use to harvest light to the degree that electrons can be shared between different reaction centers in the chloroplast.

Another technique we use which is pretty cool (or rather, hot) is the use of radioactive isotope as tracers to measure carbon uptake. On the Endeavor that activity takes place in the Rad Van, which is named for radiation and not, unfortunately, for how radical it is. By allowing algae to photosynthesize in the presence of CO2 formed with the carbon isotope 14C, we are able to track how much the carbon is taken up under a variety of different conditions.

Well, three weeks have come and gone and we put into port tomorrow. It will be nice to be back on land, but I will miss the excitement of the ocean. Today, we got a going away surprise in the form of a pod of dolphins that came near our boat and splashed around for awhile. In addition, the water around the ship was filled with a species of salp, gelatinous creatures which kind of look like sea jellies, that was bioluminescent and gave off a brilliant blue light. It was almost like the ocean knew we were leaving and decided to give us a show to send us off.

For more than 65 hours this month, NASA’s high-altitude ER-2 aircraft flew from Fairbanks over melting sea ice, glaciers, forests, permafrost, lakes, volcanoes and more. It zigged and zagged over the Beaufort Sea, and soared straight over the Bagley Ice Field.

The goal: to use a laser altimeter called MABEL to take elevation measurements over specific points and paths of land, sea and ice. To hit these marks, scientists and pilots painstakingly designed and refined flight routes. And then they adjusted those routes again to capture cloud-free views – a tricky proposition in a giant state with mountains creating complex weather systems.

A camera on the MABEL instrument captured pictures of cracked sea ice, dotted with melt ponds, during a flight to the North Pole. (Credit: NASA)

“We have targets to the north, targets to the south, and mountain ranges blocking both,” said Kelly Brunt, a research scientist at NASA’s Goddard Space Flight Center who was MABEL’s science flight planner.

Scientists studying forests, glaciers, water and more are using MABEL data to develop software programs for the upcoming ICESat-2 satellite mission, and sent Brunt lists of what they would like to be included in the Alaska campaign.

“We get everybody’s input, and start to put it on a map,” she said. She drafts routes with targets in similar weather patterns, so that if one is clear the others are likely to be as well. However, often targets are removed from a route, based on the weather assessment from the morning of the flight. During the deployment, routes are also constructed to target specific sites that were missed during previous flights for either weather or aircraft reasons. Lots of the work goes into straightening the flight line, Brunt said, since when the aircraft banks at 65,000 feet, the laser instruments swivel off their ground track and the scientists can lose miles worth of measurements.

One flight to measure sea ice was pretty direct – it took the pilot straight to the North Pole over one longitude line, circled around and came back on another. A second route involved a zig-zag pattern over the Arctic. But both routes were designed to capture a range of summer ice conditions, including melt ponds, large stretches of open water, and small openings in the sea ice, known as leads.

Flights over Alaska itself were often mapped to pass over glaciers, lakes, ocean moorings or even tide gauges that others have measured before, to compare with the data MABEL collected. Students from the Juneau Icefield Research Program (JIRP) assisted MABEL researchers by providing ground-based GPS validation for a mission that flew over the upper Taku Glacier, close to a JIRP camp. And the MABEL team collaborated with NASA Goddard scientists flying a different instrument, called Goddard’s LiDAR, Hyperspectral and Thermal (G-LiHT) Airborne Imager – the two campaigns flew some of the same paths over interior Alaskan forests.

From Fairbanks, Brunt worked with the campaign’s two pilots, Tim Williams and Denis Steele, to ensure the routes would work with the ER-2’s capabilities; and with weather forecasters to determine where to best focus efforts the following day.

In all, the campaign flew 7 flights out of Fairbanks. And today, the ER-2 – with MABEL aboard – flies back to California, collecting even more data about the elevation of the landscape along the way.